Most allergic diseases are caused by the mediators (e.g. histamine, leukotrienes, TNF-α, cytokines, etc) isolated from mast cells of tissues activated by antigen-antibody reaction and neutrophils and eosinophils in blood. The recently used drugs to treat allergic diseases are just to relieve symptoms. Therefore, it is urgently requested to develop a novel drug to treat allergy more fundamentally.
Among lung diseases, asthma is a reversible obstructive airway disease which is histologically characterized by inflammatory changes. The symptoms of asthma are caused by reversible bronchoconstriction, which are exemplified by spasmodic dyspnea, cough, and sputum, etc. The development mechanism of asthma can be described by contraction or convulsion of tracheal smooth muscle, edema in bronchial mucosa, and the increase of mucus secretion, and particularly contraction of tracheal smooth muscle is most responsible for the development of asthma. The most convincing theory to explain the reason of bronchoconstriction known so far is that when an antigen is inhaled or taken, airway hypersensitivity is induced, resulting in the broad contraction of the airway. In addition, other acceptable reasons are respiratory infection, inhalation of pungent gas or air polluted by SO2, heavy metal, asbestus, dust, etc., sudden change of weather, psychological stimulus, endocrine disorder, autonomic neuropathy, physical activities, and β-receptor blockade, etc. Chronic asthma and allergic asthma are well known to be the ones that can recur easily. These diseases have high risk of recurrence by cytokines of immune cells, and are known to be developed by autoimmunity.
Drugs for treating asthma are classified largely into bronchodilators, anti-inflammatory agents, and anti-allergic agents. The bronchodilator is exemplified by the material accelerating β2 adrenalin receptor. β2 adrenalin-agonist is the most representative airway muscle relaxant, which has been prescribed not only for the urgent care of asthma patients but also for the treatment of chronic asthma symptoms. β2 adrenalin-agonist increases intracellular c-AMP level by activating β2 adrenalin receptor and has the bronchodilating effect by relaxing tracheal smooth muscle.
The said β2 adrenalin-agonist is exemplified by salmeterol and formoterol, etc. These drugs demonstrate 12 hour persistence effect according to one time administration and can be administered alone or administered combined with adrenocortical hormones. In spite of high percentage of market share owing to the excellent medicinal effect, the said drugs have been restricted in prescription since a case was reported that an African American died of the abnormal increase of immune response according to the long term administration of such drugs, in addition to side effects such as palpitation, muscle crumps, and anxiety in patients. Therefore, it is requested to develop a novel drug with better medicinal effect but less side effect than the conventional β2 adrenalin-agonist.
Thus, the present inventors searched herb extracts that can be effectively used for the improvement of respiratory diseases including asthma. Particularly, the present inventors prepared herbal extracts from the herb mixture comprising Sophora flavascens, Radix glycyrrhizae, Flos Lonicerae, Angelicae Gigantis radix, Aralia continentalis, Inula helenium, Saposhnikoviae radix, Zizyphus spinosa, Houttuynia cordata, Forsythiae fructus, Arctium lappa, Herba epimedii, ginseng, Lithospermi radix, Sanguisorbae radix, Cnidii rhizoma, Scrophulariae radix and Polygoni cuspidati radix, and fermented products thereof using lactic acid bacteria. And, the present inventors confirmed that the herb extracts or the fermented products thereof using lactic acid bacteria were effective in the prevention or treatment of asthma, which had never been reported before, leading to the completion of the present invention.